[WIP] - Enrollment controller (#678)

Signed-off-by: David Chung [email protected]

Author: David Chung

cmd/infrakit/main.go

@@ -41,6 +41,7 @@ import (
 
 	// Supported "kinds"
 	_ "github.com/docker/infrakit/pkg/run/v0/aws"
+	_ "github.com/docker/infrakit/pkg/run/v0/enrollment"
 	_ "github.com/docker/infrakit/pkg/run/v0/file"
 	_ "github.com/docker/infrakit/pkg/run/v0/group"
 	_ "github.com/docker/infrakit/pkg/run/v0/hyperkit"

docs/controller/enrollment/example.yml

@@ -0,0 +1,79 @@
+#
+#
+#  Example for enrollment controller
+#
+#  Enrollment controller makes sure the instances in the source group (specified
+#  by the List field) are in sync with entries in the downstream instance plugin
+#  specified by Instance field.
+#
+#  This example uses swarm as backend.  So be sure your swarm on the same host
+#  is a leader via `docker swarm init`.
+#
+#
+#  1. Start up all the plugins:
+#  INFRAKIT_MANAGER_BACKEND=swarm build/infrakit plugin start manager group \
+#     enrollment:nfs \
+#     simulator:nfs-auth simulator:simulator vanilla
+#
+#  This starts up the group at 'us-east', one simulator at 'nfs' and another at 'simulator'
+#
+#  2. Commit the group to create the groups -- see the group.yml included.
+#
+#  infrakit group controller commit -y docs/controller/enrollment/group.yml
+#
+#  Verify the group has workers:
+#
+#  infrakit group/workers describe
+#
+#  3. Commit this file to create the enrollments
+#
+#  infrakit nfs controller commit -y docs/controller/enrollment/example.yml
+#
+#  4. Verify that entries are in sync: check the group describe and nfs-auth/disk (that's
+#     the Plugin specified in the Instance section of this config.
+#
+#  infrakit group/workers describe     # returns the list of nodes in the group
+#  infrakit infrakit nfs-auth/disk describe  # returns the list of corresponding enrollments
+#
+#  For each member of the group workers you should see a corresponding entry in the enrollments.
+#  Note that the instance ID of an enrollment (in nfs-auth/disk) will be different from the instance
+#  ID of a member in group/workers; however, the ID of a member of group/workers should show up as
+#  a label in the instance of nfs-auth/disk (as infrakit.enrollment.sourceID).
+#
+#  5. Try scale up the workers group
+#
+#  infrakit group/workers scale 10
+#
+#  After a while, verify enrollment:
+#
+#  infrakit nfs-auth/disk describe
+
+
+kind: enrollment
+metadata:
+  name: nfs/workers  # socket file = nfs and the name of control loop is 'workers'
+properties:
+  List: group/workers  # socket file = group and group id is 'workers'
+  Instance:
+
+    # the name of a plugin that has disk as subtype.
+    Plugin: nfs-auth/disk
+
+    # the entire Properties block here will be rendered and included as the downstream
+    # instance plugin's instance.Spec when Provision() is called.
+    Properties:
+
+       # You can include template expressions in this block; however, you need to
+       # escape the braces.
+       host: \{\{.ID\}\}
+       iops: 10
+options:
+  # This expression is a template used to select the key from each source entry
+  # of instance.Description.  Note here we escape the template tags
+  # so that template expressions don't get clobbered by infrakit template when
+  # using that as a preprocessor prior to committing.
+  SourceKeySelector: \{\{.ID\}\}
+
+  # How often to run the sync.  The string value here is in the format of Go's time.Duration.
+  # For example, 1m means 1 minute.
+  SyncInterval: 5s  # seconds

docs/controller/enrollment/group.yml

@@ -0,0 +1,30 @@
+#
+#  A group of workers
+#
+#  Start up -- plugin start should include manager, vanilla, simulator, and group
+#  Then commit
+#
+#  infrakit group controller commit -y docs/controller/enrollment/group.yml
+#
+kind: group
+metadata:
+    name: workers
+properties:
+    Allocation:
+      Size: 5
+    Flavor:
+      Plugin: vanilla
+      Properties:
+        Attachments:
+          - ID: attachid
+            Type: attachtype
+        Init:
+          - docker pull nginx:alpine
+          - docker run -d -p 80:80 nginx-alpine
+        Tags:
+          project: infrakit
+          tier: web
+    Instance:
+      Plugin: simulator/compute
+      Properties:
+        Note: custom field

docs/plugins/instance.md

@@ -1,6 +1,7 @@
 # Instance plugin API
 
-<!-- SOURCE-CHECKSUM pkg/spi/instance/* 9117db2da2ea1073a6f94b241e6c6a9a0a9048d452c44631323150dfeffdfde2b8c5ba85e274fabe -->
+<!-- SOURCE-CHECKSUM pkg/spi/instance/* 6b3c98bed4470312a41376f651cee99a9e35ffb09117db2da2ea1073a6f94b241e6c6a9a0a9048d452c44631323150dfeffdfde2b8c5ba85e274fabe -->
+
 
 ## API
 

pkg/cli/v0/group/cmd.go

@@ -15,15 +15,14 @@ var log = logutil.New("module", "cli/v1/group")
 func init() {
 	cli.Register(group.InterfaceSpec,
 		[]cli.CmdBuilder{
-			//Group,
+			// Group,
 			Ls,
 			Inspect,
 			Describe,
 			Commit,
 			Free,
 			Destroy,
-			Size,
-			SetSize,
+			Scale,
 			DestroyInstances,
 		})
 }
@@ -42,8 +41,7 @@ func Group(name string, services *cli.Services) *cobra.Command {
 		Commit(name, services),
 		Free(name, services),
 		Destroy(name, services),
-		Size(name, services),
-		SetSize(name, services),
+		Scale(name, services),
 		DestroyInstances(name, services),
 	)
 

pkg/cli/v0/group/scale.go

@@ -0,0 +1,91 @@
+package group
+
+import (
+	"fmt"
+	"os"
+	"strconv"
+
+	"github.com/docker/infrakit/pkg/cli"
+	"github.com/docker/infrakit/pkg/plugin"
+	"github.com/docker/infrakit/pkg/spi/group"
+	"github.com/spf13/cobra"
+)
+
+// Scale returns the scale command
+func Scale(name string, services *cli.Services) *cobra.Command {
+
+	scale := &cobra.Command{
+		Use:   "scale <groupID> [new-target]",
+		Short: "Returns size of the group if no args provided. Otherwise set the target size.",
+		RunE: func(cmd *cobra.Command, args []string) error {
+
+			pluginName := plugin.Name(name)
+			_, gid := pluginName.GetLookupAndType()
+
+			size := -1
+
+			if gid == "" {
+				// if gid is not known, then we need it to be provided
+				switch len(args) {
+
+				case 0:
+					cmd.Usage()
+					os.Exit(1)
+				case 1:
+					gid = args[0]
+				case 2:
+					gid = args[0]
+					sz, err := strconv.Atoi(args[1])
+					if err != nil {
+						return err
+					}
+					size = sz
+				default:
+					cmd.Usage()
+					os.Exit(1)
+				}
+			} else {
+				// if gid is not known, then we need it to be provided
+				switch len(args) {
+
+				case 0:
+					size = -1
+				case 1:
+					sz, err := strconv.Atoi(args[0])
+					if err != nil {
+						return err
+					}
+					size = sz
+				default:
+					cmd.Usage()
+					os.Exit(1)
+				}
+			}
+
+			groupPlugin, err := LoadPlugin(services.Plugins(), name)
+			if err != nil {
+				return nil
+			}
+			cli.MustNotNil(groupPlugin, "group plugin not found", "name", name)
+
+			groupID := group.ID(gid)
+			target, err := groupPlugin.Size(groupID)
+			if err != nil {
+				return err
+			}
+			fmt.Printf("Group %v at %d instances", groupID, target)
+
+			if size > -1 {
+				err = groupPlugin.SetSize(groupID, size)
+				if err != nil {
+					return err
+				}
+				fmt.Printf(", scale to %d", size)
+			}
+
+			fmt.Println()
+			return nil
+		},
+	}
+	return scale
+}

pkg/controller/enrollment/controller.go

@@ -0,0 +1,57 @@
+package enrollment
+
+import (
+	"github.com/docker/infrakit/pkg/controller"
+	enrollment "github.com/docker/infrakit/pkg/controller/enrollment/types"
+	"github.com/docker/infrakit/pkg/controller/internal"
+	"github.com/docker/infrakit/pkg/discovery"
+	logutil "github.com/docker/infrakit/pkg/log"
+	"github.com/docker/infrakit/pkg/manager"
+	"github.com/docker/infrakit/pkg/types"
+)
+
+var (
+	log    = logutil.New("module", "controller/enrollment")
+	debugV = logutil.V(200)
+)
+
+// NewController returns a controller implementation
+func NewController(plugins func() discovery.Plugins, leader manager.Leadership,
+	options enrollment.Options) controller.Controller {
+	return internal.NewController(
+		leader,
+		// the constructor
+		func(spec types.Spec) (internal.Managed, error) {
+			return newEnroller(plugins, leader, options), nil
+		},
+		// the key function
+		func(metadata types.Metadata) string {
+			return metadata.Name
+		},
+	)
+}
+
+// NewTypedControllers return typed controllers
+func NewTypedControllers(plugins func() discovery.Plugins, leader manager.Leadership,
+	options enrollment.Options) func() (map[string]controller.Controller, error) {
+
+	return (internal.NewController(
+		leader,
+		// the constructor
+		func(spec types.Spec) (internal.Managed, error) {
+			log.Debug("Creating managed object", "spec", spec)
+			return newEnroller(plugins, leader, options), nil
+		},
+		// the key function
+		func(metadata types.Metadata) string {
+			return metadata.Name
+		},
+	)).ManagedObjects
+}
+
+func (l *enroller) started() bool {
+	l.lock.RLock()
+	defer l.lock.RUnlock()
+
+	return l.running
+}